Network Engineer Job Interview – What to Expect?


Inteviewer is waiting for applicantsIf you are invited for an interview for network engineer position, you need to realize several things before beginning with your preparation. Firstly you should know what technology does your perspective employer use. Do they use Cisco or Juniper? Or do they apply something different? Needless to say, technical interview questions will differ in each case, so you need to prepare for the questions related to the particular solution employer uses.

Who is going to lead the interview with you is another important question. Interviews in big companies have typically several rounds. If you are going for the first round, it is not uncommon that external HR person or an HR generalist is going to lead the interview with you. This person knows nothing about Cisco, Juniper and network engineering at all… It is a general employee, who interviews you for a reason. His goal is to assess your motivation to do the job, your communication skills, your requirements as well as desires and your personality. Based on the results of this screening interview, you may, as well as may not, proceed to the second round. Just then you will deal with technical questions mostly.


Who will lead your interview?

Job interview for a position of network engineer can be conducted by a manager, by HR person, by IT specialist or by senior network engineer himself. As you can guess, each time the questions will differ and each person looks for something else in you. To give you basic advice, the less professional in network engineering the interviewer is, the more you need to focus on creating good relationship with him. Personal preferences play a huge role in such a case… By presenting a motivation and determination to do a good job and showing respect you have a good shot to be chosen.
It is so, because this person can not assess your real skills in network engineering. You can tell him whatever you want… Therefor, it makes no sense to try to stun him or her with it. On the other hand, if you are interviewed by a technician or by specialist in the field, high motivation and excellent communication skills will not save you, if you do not have the actual knowledge of technology. Let’s have a look at the questions you can expect to get.


Personal and behavioral questions

You will need to respond to these questions in an interview with a non-technician, or in the first screening interview.

You should not underestimate these personal and behavioral questions. I suggest you to think about it for a while, or to use sample answers from this website as your inspiration. Most of these questions has nothing to do with the actual job, I know it. But they represent a part of interview process and in order to get a job, you just can not underestimate it. You need to accept the process as it is.


Technical questions

Cisco illustrationIf you are interviewed by a technician (typical in start-ups and smaller companies, or during second round of interviews in bigger companies), the questions will be very different. It will go about practical network engineering questions. Let’s have a look at it:

  • Why do you prefer Cisco (Juniper) to other solutions?
  • Can you name the advantages of Cisco (Juniper)?
  • What Firewall do you personally consider as the most secure one and why?
  • Do you know what means to bridge the VPNs? Where it is used?
  • What is the reason why we shoudl use secondary router also?
  • What are the layers in TCP/IP protocol?
  • Can you define various types of Sockets and where we can find it?
  • What means the following address of subnet mask? (They will give you some address and you should interpret it.)
  • What represents the majority part of worldwide NSP revenue today?
  • How would you reduce the watts per bit to ensure the higher efficiency of a computer network? Describe the process and the steps you will take.
  • Describe the latest time you had to troubleshoot a network. What was the problem and what steps did you take to eliminate the problem?
  • What do you see as future of network engineering?
  • From your point of view, what is more important nowadays: security or speed?
  • Write a function, and the output should be the function itself.
  • When you receive a crash dump for a process from a particular customer, Is it possible to know the line number of which function has caused the problem?


As you can guess, there are thousands various technical questions. It does not matter if we speak about Juniper or Cisco. To be honest, nobody can answer every possible technical question… The most important thing to do in this case is to show that you know how to look for help and how to solve the problem quickly, for example by looking into the support forums or doing split tests by yourself. That’s it. We wish you good luck in your interview!